Hydrochloric Acid → 1'-isopropyl-4',6'-dihydrospiro[piperidine-4,5'-pyrazolo[3,4-c]pyridin]-7'(1'H)-one

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Reaction Steps

To a solution of tert-butyl 1′-isopropyl-7′-oxo-1′,4′,6′,7′-tetrahydrospiro[piperidine-4,5′-pyrazolo[3,4-c]pyridine]-1-carboxylate (100 mg, 0.29 mmol) in 4 mL ethyl acetate was added 4 N HCl in dioxane (2 mL). After stirring 30 minutes at room temperature, methanol (1 mL) was added and the resultant solution was stirred for 5 hours at room temperature. The volatiles were removed under reduced pressure and the resultant colorless solid triturated with 1:1 acetonitrile/dichloromethane to yield 71 mg of the title compound as a colorless solid. 1H NMR (400 MHz, DMSO-d6, δ): 8.72 (br. s., 2H), 8.05 (s, 1H), 7.37 (s, 1H), 5.36 (m, 1H), 3.15 (m, 2H), 3.05 (m, 2H), 2.78 (s, 2H), 1.78 (m, 4H), 1.33 (d, J=6.6 Hz, 6H).

Provenance & Evidence